A boot virus infects PCs during the system start-up process. Although boot viruses are less common than other types of viruses, they tend to be more virulent when they strike, McAfee officials said.
BootShield works by masking the boot sector from viruses at start-up. It then scans the system for viruses. Once the system is certified clean, BootShield copies itself into the boot sector and relocates the boot sector in a secure area. If a virus tries to modify the boot sector, the PC will shut down. BootShield includes ImageStor, a data recovery utility.